At a fundamental level, all computer systems, including the initial primitive vacuum-tube-based computer systems developed in the 1940's, are data-storage machines which execute symbol-transformation operations on stored data. Initially, data was stored in small, volatile electronic memories within computer systems and on punched cards input to computer systems. As the capabilities of computer systems, and uses to which computer systems were put, rapidly expanded, a wide array of different types of volatile and non-volatile data-storage components were developed for computer systems, as well as computational subsystems and logical entities to facilitate creation, storage, retrieval, alteration, input, and output of data. Ultimately, separate database-management systems were developed to provide even higher-level database-management functionality.
Currently, very complex and highly capable database-management systems of a variety of different types are commercially available for managing data on a broad range of computer systems from personal computers all the way up to highly complex, distributed computer systems in which data is stored and managed over large numbers of computer systems and mass-storage systems interconnected by a variety of different communications media. Relational-database-management systems, based on a relational algebra that provides relatively simple and logical constructs and algebraic operations on those constructs, were initially developed in the late 1960's and 1970's, and continue to provide useful, flexible, and powerful database management in today's sophisticated, highly-distributed computing environments. The capacities and capabilities of relational-database-management systems have continued to increase, in parallel with the evolution of computing hardware and operating systems, and many powerful and useful tools and utilities for monitoring the performance of, and modifying, relational-database-management systems have been developed to provide managers and administrators with needed functionality for administering data storage, data retrieval, and querying of stored data in modern computing environments. The development of database monitoring and management tools continues to attract large efforts from researchers, academicians, database-management-system designers and vendors, designers and manufacturers of computer hardware, and, ultimately, individual and corporate users of database-management systems.